Fireproofing compositions



Patented Feb. 22, 1949 2.462.803 i- FIREPBOOFING COMPOSITIONS Kenneth S.Campbell and Jack E. Sands, New

leans,

La., assignors to the United States of America as represented by theSecretary of Agriculture No Drawing. Application March 23, 1945,

Serial No. 584,484

9 Claims. (01. 260-'28) (Granted under the act of March 3, 1883, asamended April 30, 1928; 370 O. G. 757) This application is made underthe act of March 3, 1883, as amended by the act of April 30, 1928, andthe invention herein described, if patented, may be manufactured andused by or for the Government of the United States of America forgovernmental purposes without the payment to us of any royalty thereon.

This invention relates to flameproofing and is I l more particularlyconcerned with the flameproofing of organic combustible materials suchas those having a cellulose or protein base of either natural plantfibers or artificial fibers. Specific examples of such materials aretextiles, such as cotton, silk, rayon, wool, mohair, nylon; braidedmaterials such as ropes and cords; felted materials such as leather,either artificial or natural, paper, and so forth.

This invention embraces new compositions of matter which are applied tothe material to be treated for the purpose of flameproofing it, saidcompositions having a fire-retarding action which remains substantiallyundiminished after a large number of commercial laundering treatments.The compositions are also effective when applied to cellulosic fabric ina quantity insuflicient to change the physical properties of the fabricto the degree of rendering it unsuitable for clothing purposes. A fabricsuitable for clothing purposes would be one which, after flameproofingtreatment, has retained the major portion, at least 60%, of its originalair-permeability, has lost practically none of its original flexibility,and has not acquired any undesirable properties such as stickiness, orobjectionable softening or stiffening on exposure to extremes of heatand cold.

In the prior art, use is made of compositions of certain metallic oxidesand chlorine-containing substances to produce flame-retarding finishes.Vinyl chloride resin has been applied to cloth flameproofed by the tinoxide method, the purpose of the vinyl chloride resin being, in part, tosuppress the afterglow which is characteristic of the tin oxidetreatment. Other treatments involve the use of heavier oxides inconjunction with the chlorinated compounds.

The use of the treatment of the prior art requires the addition to thefabric of such an amount of foreign material that the original weight ofthe fabric is increased by from 35% to 80%, or more. At the same time,the air-permeability, and consequently the usefulness of the fabric, asclothing material, is reduced to almost nothing. By the use of ourinvention, the same degree of fire resistance can be obtained withoutincreasing the fabric weight more than about the exact percentagedepending on the initial I weight and weave of the fabric.Air-permeability is decreased by our treatment only to a moderate degreeresulting in a fabric which is substantially as comfortable to thewearer as the original untreated cloth.

In the prior art, a considerable proportion of the materials added, inaddition to the oxide and chlorinated substances, consists of suchsubstances as calcium carbonate and colored pigments which are necessaryto prevent excessive deterioration of the cellulose subtrate due to boththe gradual hydrolysis or decomposition of the chlorine-containingsi'ibstance, forming hydrochloric acid, and the catalytic effect of theultraviolet in sunlight in the presence of both the metallic oxide andthe chlorinated substance. In our invention, however, both of thesecauses of degradation are neutralized by the presence of a water-solubleurea-formaldehyde condensation product which acts in a bufferingcapacity and also as a binding agent for the oxide pigment. For example,samples of bleached cotton duck which had been fiameproofed by ourprocess, were completely exposed to the weather for six months. At theend of this time it showed no loss in tensile strength. This same duck,untreated, lost approximately of its strength in the same period oftime.

' In the prior art, colored pigments are added for protection againstthe efiect of light. Our invention, however, makes possible theproduction of a permanently flameproofed fabric resistant todeterioration by exposure, without the addition of any pigments.

In the prior art, the preferred method of application of the compositionis in the form of a volatile, inflammable, solvent solution. Such asolution produces a fire hazard. In our invention, the preferred use ofa non-inflammable emulsion has distinct advantages over the solution ofthe prior art. For example, the use of an emulsion reduces the amount oforganic solvent necessary, thus lowering the cost, and at the same timeeliminates the fire hazard; also an emulsion is the practical means bywhich water-soluble urea-formaldehyde condensation product may becombined with the solvent soluble ingredients to form a singlehomogeneous composition.

In general, our invention comprises the impregnation of organiccombustible materials, particularly textile and cellulosic materialswith an emulsion containing a metallic oxide selected from the groupconsisting of antimony oxide, tinoxide and arsenic oxide, chlorinated.paraflln depend in large part on the looseness or tightness of theweave, and initial weight and density of the cloth. For example, lightweight material of a very open weave may require no parafin wax of the42%-4E chlorine variety whatever, while a heavy duck, in order to retainits flexibility after treatment, may require about equal parts. of42%-45% and 70% chlorine content paraflln wax. Some loosely wovenfabrics may profit from the slight stiffening and binding efl'ectresulting from the use of a high percentage of a highly chlorinated typeof paramn wax. In some cases, it may prove desirable to use a proportionof 70% chlorine content parafiln wax which producesconsiderable'stiflness in the dried fabric, and then break down thestiffness by mechanical means, as for example, on a buttonbreaker.

The following examples are illustrative of our invention:

Example I Bleached cotton fiat duck, weighing approximately 7 ounces persquare yard, is impregnated by padding, with the following oil-in-watertype emulsion: I

' Per cent by weight In the preparation of this emulsion the chlorinatedpaiaflin wax and the stearic acid are dissolved in the mineral spirits(boiling range 350- 375" F.) and this solution added gradually, withstirring, to an aqueous solution containing the urea-formaldehydecondensation product and the triethanolamine. The antimony oxide is thendispersed in the formed emulsion.

The cloth is then impregnated in the above emulsion in such a manner asto cause it to increase its weight, when dried and finished, byapproximately 30%. This control of weight increase of the cloth, as aresult of impregnation, may be accomplished by' ordinary suitable meanssuch as pressure-rollers, doctor blades, and so forth. The cloth is thendried, after impregnation, by the most convenient means available andthen subjected to a few minutes exposure to a temperature in the rangeof about 140 to 150 C., the time of exposure being shorter, the higherthe temperature, the purpose being the complete polymerization of theurea-formaldhyde condensation product. The cloth is then washed in a hotdilute soap solution, preferably at a boil, rinsed. and dried,preferably on a frame. The dried cloth may then be finished by some typeof mechanical breaking-down treatment. if desired.

Fabric treated as outlined has been found to satisfy the fire test ofFederal Specification CCC-D-746 after 12 successive wash tests carriedout as'specified in the ofliciai Wash test No. 3 of the AmericanAssociation of Textile Chemists and Colorists. Also, after sixmonthstotal exposure, this sample was found to have suilered no lossin-tensile strength.

. Eazample II" Cotton herringbone twill fabric, dyed O. D. #7,

weighing 8.5 ounces per square yard, is impregnated by padding, with thefollowing water-in-oil type emulsion:

' Per cent by weight Chlorinated paraflln wax Urea-formaldehydecondensation product 9.00 Antimony oxide (about 325 mesh) 9.90

In the preparation of this emulsion, the first three listed componentsare dissolved in the mineral spirits (boiling range 350-375 F), and tothis solution is added, with stirring, the aqueous solution ofurea-formaldehyde condensation product. The antimony oxide is thendispeised in the thus formed emulsion.

The cloth is impregnated'in the above emulsion in such a manner as tomake the final dry The finished cloth resulting from the above treatmenthas been found to meetthe fire test of Federal Specification CCC-'D-746after fifteen successive wash tests, and other tests as described inExample I.

Having thus described our invention, we claim:

1. A 'flameproofing composition comprising chlorinated paraflin wax, awater-soluble ureaformaldehyde condensation product, and antimony oxide,emulsified in water with an emulsifying agent.

2. A process of flameproofing an organic combustible material comprisingimpregnating said material with an aqueous emulsion containingchlorinated paraflin wax, a. water-soluble ureaformaldehyde condensationproduct, and antimony oxide, drying the impregnated material, and.heating thedried material to polymerize the urea-formaldehydecondensation product.

3. An organic combustible material impregnated with an aqueous emulsioncontaining chlorinated paraflin wax, a water-soluble urea-formaldehydecondensatlon product, and antimony oxide, dried, and havingtheurea-formaldehyde 70 percent, by weight, of chlorine, a water-solubleurea-formaldehyde condensation product, antimony oxide, water,'and anemulsifying agent, said chlorinated paraflin wax, urea-formaldehydecondensation product, and antimony oxide, being present, on the basis ofthe total weight of the ingredients, in the percentages of about from16.00 to 20.70 percent, from 9.00 to 9.60 percent, and from 6.40 to 9.90percent, respectively.

5. A process of fiameproofing an organic combustible material comprisingimpregnating said material with a flameproofing composition comprisingchlorinated parafiin wax containing from 42 to '70 percent, by weight,of chlorine, a watersoluble urea-formaldehyde condensation product,antimony oxide, water, and an emulsifying agent, said chlorinatedparaflin wax, urea-formaldehyde condensation product, and antimonyoxide, being present, on the basis of the total weight of theingredients, in the percentages of about from 16.00 to 20.70 percent,from 9.00 to 9.60 percent, and from 6.40 to 9.90 percent, respectively,drying the impregnated material, and heating the dried material topolymerize the urea-formaldehyde condensation product,

6. An organic combustible material impregnated with a flameprooflngcomposition comprising chlorinated paraflin wax containing from 42 to 70percent, by weight, of chlorine, a water-soluble urea-formaldehydecondensation product, antimony oxide, water, and an emulsifying agent,said chlorinated paraflln wax, urea-formaldehyde condensation product,and antimony oxide, being present, on the basis of the total weight ofthe ingredients, in the percentages of about from 16.00 to 20.70percent, from 9.00 to 9.60 percent, and from 6.40 to 9.90 percent,respectively, dried, and having the urea-formaldehyde condensationproduct polymerized.

7. A flameproofing composition comprising chlorinated paraflln waxcontaining from 42 to 70 percent, by weight, of chlorine, awater-soluble urea-formaldehyde condensation product, antimony oxide.water, and an emulsifying agent, said chlorinated paraflin wax,urea-formaldehyde condensation product, and antimony oxide, beingpresent, on the basis of the total weight of the ingredients, in thepercentages of about 16.00 pierecfi nt, 9.60 percent, and 6.40 percent,respect v 8. A process of flameproofing an organic combustible materialcomprising impregnating said material with a fiameproofing compositioncomprising chlorinated parailin wax containing from 42 to '70 percent,by weight, of chlorine, a watersoluble urea-formaldehyde condensationproduct, antimony oxide, water, and an emulsifying agent, saidchlorinated parafiin wax, urea-formaldehyde condensation product, andantimony oxide, being present, on the basis of the total weight of theingredients, in the percentages of about 16.00 percent, 9.60 percent,and 6.40 percent,'respec-. tively, drying the impregnated material, andheating the dried material to polymerize the ureaformaldehydecondensation product.

9. An organic combustible material impregnated with a flameproofingcomposition comprising chlorinated paraflin wax containing from 42 to'70 percent, by weight, of chlorine, a watersoluble urea-formaldehydecondensation product, antimony oxide, water, and an emulsifying agent,said chlorinated paraflin wax, urea-formaldehyde condensation product,and antimony oxide, being present, on the basis ofthe total weight ofthe ingredients, in the percentages of about 16.00 percent, 9.60percent, and 6.40 percent, respectively, dried, and having theurea-formaldehyde condensation product polymerized.

KENNETH S. CAMPBELL. JACK E. SANDS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Bacon Dec. 24, 1946 FOREIGN PATENTSCountry Date Switzerland June 1, 1939 OTHER REFERENCES Number Number

